Lock mechanisms



May 12,1970 E. LAWRENCE, JR 3,511,069

LOCK macnmusmsv Filed March 26, 1968 2 Sheets-Sheet 1 FIGJ 0* I VFIG.2

23 9 FIG.5 a ug. I

I INVENTOR. l L. fizz/my law/mag:

United States Patent 3,511,069 LOCK MECHANISMS Ewing Lawrence, Jr., Ponte Vedra Beach, Fla., assignor to S L and F Enterprises, Incorporated, Jacksonville, Fla., a corporation of Florida Filed Mar. 26, 1968, Ser. No. 716,099 Int. Cl. Eb 63/00 US. C]. 70-15 20 Claims ABSTRACT OF THE DISCLOSURE A key operated lock including a lock bolt having an outwardly opening notch within the side thereof and dogging means continually urged and movable into and out of engagement within the notch when the notch and dogging means are in alignment. Means are provided for maintaining the dogging means inoperative when the lock bolt is fully extended, and the dogging means are responsive to and movable into engagement within the notch upon a predetermined retracting movement of the lock bolt from its fully extended position. The dogging means moves into the notch after a predetermined delay from the initial movement of the lock bolt from its fully extended position toward its retracted position. The lock bolt is freely retractable without the dogging means moving into the notch upon movement of the lock bolt beyond the predetermined retracting movement in less time than the predetermined delay of the dogging means.

BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to improvements in locks, more particularly the invention pertains to an improved lock which includes means for preventing the unauthorized actuation of the lock mechanism by picking tools or the like.

A general object of this invention is to provide an improved lock which is substantially non-pickable.

Heretofore it has been stated that any lock which can be opened by means of a key can be operated by means of a pick. The conventional lock pick consists of a single blade or a series of blades or tumbler actuators which operate on the various tumblers until finally all of the parting lines (in a barrel and cylinder lock) are lined up with the exterior of the plug or barrel, after which the plug or barrel may be rotated the same as by a key. How ever the opening of a lock by means of known picks takes an appreciable amount of time. This invention is based upon this fact and includes means for dogging or otherwise rendering the lock opening or operating means in; effective after the lapse of a certain amount of time after attempted picking of the lock has begun.

Another general object of the invention is to provide a lock which may be readily actuated only by an authorized person possessing a properly cut, smooth fitting key.

Still another object of the subject invention is to provide an improved lock which embodies devices operating to prevent any unauthorized movement of the movable engaging or securing member when the parts of the lock are engaged.

Yet another object of the instant invention is to provide an improved lock which includes devices operative to prevent the unauthorized movement of the movable securing or locking member when the parts of the lock are engaged, the device being controlled by means which are automatically operable once the lock bolt has been fully extended and engaged.

Still a further object of this invention is to provide an 3,511,069 Patented May 12, 1970 improved lock which embodies a device to prevent any unauthorized movement of the movable securing member of the lock when the parts of the lock are engaged, and in which the device can be made to be non-operative by a normal use of the lock key when it is desired to open the lock.

These objects are accomplished in general by providing a device associated with the well-known key operated barrel and cylinder lock, which device is actuated by the initial unlocking motion of the bolt or securing member of the lock such that the inertia opposing the motion of a movable member which is a part of the device determines the length of time in which the bolt or securing member of the lock can be further moved into or toward the unlocked position. The inertia of the movable member is so established as to limit the time during which the bolt or other securing member can be withdrawn, to a time less than that required for manipulation of the lock by means other than a smooth fitting, properly cut key.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a cross-sectional, elevational view through a locking arrangement showing one embodiment of the device of this invention in use therewith;

FIG. 2 is a transverse-sectional view taken along line 22 of FIG. 1;

FIG. 3 is an enlarged view of a section of the upper portion of FIG. 2;

FIG. 4 is a view similar to FIG. 3 with the lock bolt shown in a second position;

FIG. 5 is a view similar to FIG. 3 with the lock bolt shown in a third position;

FIG. 6 is a perspective view of a second embodiment of the device of this invention installed on the body of a lock;

FIG. 7 is a transverse-sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is a transverse sectional view taken along line 8--8 of FIG. 7;

FIG. 9 is a view similar to FIG. 8 with the lock bolt shown in a second position;

FIG. 10 is a view similar to FIG. 8 with the lock bolt shown in a third position;

FIG. 11 is an enlarged partial top view of the apparatus shown in FIG. 6;

FIG. 12 is a cross-sectional view taken along line 12 12 of FIG. 9;

FIG. 13 is a cross-sectional view taken along line 13- 13 of FIG. 10; and

FIG. 14 is a view similar to FIG. 8 with the apparatus having been rotated through an angle of degrees.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, and in particular to FIGS. 1 and 2 thereof, the device 10 of this invention is shown in connection with a lock 12 which is operated by a key 14 or other like means. The device 10 and lock 12 are shown in FIGS. 1 and 2 in connection with a door or cover 16 for a coin receiving box or receptacle 18, the door being depicted in an opened position by dashed-line configuration 20. Although the device 10 is shown in FIGS. 1 and 2 in connection with a generally upright lock, having a lock bolt 22 which travels in a generally vertical direction, the

same can be used in numerous other arrangements and applications.

Lock bolt 22 of lock 12 is securable behind a flange or plate 24 When door 16 is in the closed position. Flange 24 is secured to or is a part of a housing 26 which surrounds the coin receiving box or receptacle 18.

The device is secured in housing 26 adjacently behind flange 24 and adjacently above the body of lock 12 when door 16 is in the closed position. Device 10 can be secured within housing 26 by encasement within plastic foam resilient mounting as at 28, which is then cemented to housing 26, or the same may be installed by other like means.

Device 10 includes a stationary member 30 and a pivotal member 32 which is mounted to stationary member 30 by means of a pin 34 about which it is freely pivotable. Pivotal member 32 acts as a latch to prevent unauthorized withdrawal of lock bolt 22 or unauthorized operation of the lock such that door 16 may be opened. Lock bolt 22 is extendable from its completely retracted or fully recessed position within the body of lock 12, as depicted in the dashed line configuration 36 in FIG. 4, to its fully extended position at 56 in FIG. 5.

An opening 40 is provided in stationary or mounting member 30 of the device to permit pivotal member 32 to freely pivot therein about pin 34. Opening 40 within stationary member 30 is further enlarged at 42 to provide for the entry of lock bolt 22 into and out of the opening within stationary member 30, to permit the bolt to operate smoothly and without obstruction. Lock bolt 22 is provided with a slot 44 on its side into which a dog or pawl 46 on the lower end of pivotal member 32 can fit. Dog 46 is connected to the main portion of member 32 by an arm 47. Due to the weight distribution of pivotal member 32 and the mounting of pin 34 therein, dog 46 is constantly being urged by the force of gravity towards the notched or slotted side 48 of lock bolt 22, and into notch 44 when the two are aligned. Once dog 46 has engaged within notch 44 further withdrawal or downward movement of lock bolt 22 and unlocking of the lock becomes impossible, as the upper edge of notch 44 engages with upper edge of dog 46, as depicted in FIG. 2, and further downward travel of lock bolt 22 is prevented. Further attempted downward travel of lock bolt 22 places dog 46 in compression between the upper edge of notch 44 and the upper surface of lock body 12.

When door 16 has been moved from its opened position 20 (see FIG. 1) to its closed position, lock bolt 22 may be made to begin its extension from its fully retracted position, as depicted in FIG. 4 by dashed-line configuration 36, by rotating key 14 in the usual clockwise direction. In extending bolt 22 from fully retracted position 36 (see FIG. 4), the bolt first moves upward to a position in which it contacts dog 46 of pivotal member 32, such as depicted at 50 in FIG. 4. The inner end of dog 46 is chamfered at 52, such that when this end of the dog is contacted by the upper edge 23 of upwardly moving bolt 22, member 32 is pivoted about pin 34 whereby dog 46 pivots outwardly to the right of bolt 22 to prevent any interference with the extension of the bolt. This could also be accomplished by chamfering the upper-right edge of bolt 22, or member 32 could be mounted in a manner that would not require the chamfering of dog 46 at 52. As the bolt 22 continues to be extended or moved upwardly by the continued clockwise turning of key 14, it will assume position 54, as depicted in FIG. 3, wherein dog 46 enters notch 44 as member 32 rotates in a clockwise direction by the force of gravity. Upon further rotation of key 14 and the complete extension and upward movement of bolt 22 into position 56, as depicted in FIG. 5, upper edge 23 of bolt 22 contacts a tab 58 on the lower portion of pivotal member 32. Tab 58 is slightly offset to the right from a vertical line through pivotal point 34 (when pivotal member 32 is in the generally vertical or at rest position as depicted in FIG. 3) such that upon contact of this tab by bolt 22 and further slight extension or upward movement of the bolt, pivotal member 32 is rotated in a counterclockwise direction whereby dog 46 is disengaged from notch 44. In this completely extended position 56, bolt 22 is freed from dog 46 and may be retracted or moved downwardly to open to lock if the same is manipulated by a rapid turning of the lock with a properly cut, smooth fitting key such as at 14.

If it is attempted to operated to operate the lock and retract lock bolt 22 by other than a properly cut, smooth fitting key, as at 14, such as picking tools or the like, bolt 22 will be returned to position 54 of FIG. 3 with dog 46 engaged within notch 44 before the would-be-picker of the lock is able to free all of the tumblers therein. Upon further attempted picking of the lock, bolt 22 will move into the position depicted in FIG. 2, wherein the top of notch 44 contacts the top of dog 46, and further downward movement of bolt 22 will be prevented.

When a properly cut, smooth fitting key is used to open the lock and withdraw or move downwardly lock bolt 22 from its fully extended position 56 (FIG. 5) to its fully retracted position 36 (FIG. 4), the withdrawal can be accomplished by a rapid turning of the key such that bolt 22 is retracted more rapidly than member 32 can pivot and its attached dog 46 operate to engage within notch 44, due to its inertia or sluggishness in responding to the force of gravity when released from its disengaged position depicted in FIG. 5. This is to say, that by using a properly cut, smooth fitting key the lock may be operated in its normal manner simply by withdrawing lock bolt 22 faster than the time required for pivotal member 32 and its attached dog 46 to swing into notch 44 within the side of bolt 22 after release thereof from its disengaged position as depicted in FIG. 5.

The inertia of pivotal member 32 and attached dog 46 results in a small time delay between the releasing thereof by lock bolt 22 from the position as depicted in FIG. 5 and the full swing thereof to the position as depicted in FIG. 3. This time delay is the key factor to the effective operation of the device of the instant invention. When a properly cut, smooth fitting key is used to operate the lock and the same is rotated in a rapid manner, dog 46 does not have time to engage notch 44 within bolt 22 before the same has been retracted, whereby the lock may be opened in a normal manner.

The use of device .10 has been depicted in FIGS. 1-5 in connection with a lock whose bolt operates in a generally upright position and in which the at rest position of pivotal member 32 is similar to that as depicted in FIG. 3. Device 10 could also be used in other locking arrangements and adaptations wherein the force of gravity acts to bring dog 46 into engagement with notch 44. If the lock arrangement was such that the force of gravity did not tend to engage dog 46 within notch 44 then small, weak springs or other like means could be provided between the slanted top portion of pivotal member 32 and housing 30 or between the side of arm 47 and housing 30 to urge dog 46 into engagement with notch 44. In such other arrangements the operation of the system would still be relying upon the inertia of pivotal member 32 and the small time delay resulting therefrom between its disengaged and engaged positions.

A second embodiment of the device of this invention is depicted in FIGS. 6 through 14. This device 70 is mounted on and secured to the body of lock 12, whereas in the embodiment depicted in FIGS. 1 through 5 device 10 is mounted on and attached to the housing 26 closely adjacent the flange or plate 24 behind which lock bolt 22 is secured.

Device 70 includes a stationary member 72 which is mounted on the back of the body of lock 12 by cementing or other means, a housing 74 which fits within and which is secured to member 72 such as by cementing or the like, and a movable member 76. Movable member 76 includes a generally upright portion 78 having a laterally extending arm 80 adjacent its lower end and a generally horizontal portion 82 terminating in a latch member 84. Latch 84 is engageable within notch 44 within the side of lock bolt 22 to secure or maintain bolt 22 in its extended position (as depicted in FIG. to prevent the complete withdrawal and retraction of bolt 22 with the consequent opening of lock 12 by a would-be picker when it is attempted to operate the lock by any means other than a properly cut, smooth fitting key. Movable member 76 further includes a laterally extending portion 85 running along the upper end of portion 78 and along a part of portion 82. Portion 85 adds weight to the upper left portion of member 76 to aid the force of gravity to urge latch 84 into engagement with notch 44.

Movable member 76 rests within housing 74 and is movable within an opening 86 provided in housing 74. Member 76 is further pivotable within opening 86 about a fulcrum or knife edge 88, provided within housing 74, from the position 90 depicted in FIG. 8 when lock bolt 22 is fully extended to the position 92 as depicted in FIG. 9 when upright member 78 abuts the left side of opening 86 within housing 74. Position 92 of movable member 76, as depicted in FIG. 9, is attained at those times when latch 84 is engaged within notch 44 or when lock bolt 22 is completely withdrawn or recessed Within the body of lock 12.

Movable member 76 is additionally pivotable about a second fulcrum or knife edge 94 within housing 74 at those times when lock bolt 22 is moving upward from its fully recessed or retracted position and when bolt 22 is moving from its position 92, as depicted in FIG. 9 within latch 84 engaged within notch 44, to its fully extended position 90, as depicted in FIG. 8 with latch 84 resting against the right side of bolt 22. An upwardly extending tab 96 is provided on the end of laterally extending member 80 to maintain a portion of member 76 within a cut-out 98 within housing 74 behind or to the right of knife edge 94.

When in operation, the door 16 or other like device to which the body of lock 12 is secured, is first closed or placed in the position in which the lock can be locked, the door being secured by the extended lock bolt 22. Once the door has been closed, the extension of lock bolt 22 may be begun by inserting properly cut, smooth fitting key 14 within the key hole of the lock and turning of the same in the usual locking direction. When bolt 22 is completely retracted or recessed within the body of lock 12, latch 84 extends over a portion of the top of the bolt. As bolt 22 begins its upward movement, it will raise latch 84 and the remainder of member 76 connected thereto. Member 76 will continue moving upward with bolt 22 until lateral extension 80 thereof contacts fulcrum or knife edge 94, at which point member 76 will pivot such that latch 84 moves to the right off of and away from bolt 22. When member 76 has pivoted to the right such that latch 84 is no longer in contact with the upper edge of bolt 22, member 76 will fall downward within opening 86 of housing 74 until lateral extension 80 thereof rests upon fulcrum of pivot point '88 as depicted in FIG. 8.

If the key is rotated at a very slow rate during the extension or upward travel of bolt 22, it is possible for member 76 and latch 84 to assume position 92 as depicted in FIG. 9 with latch 84 engaged within notch 44 of the bolt. If this happens, latch 84 can be made to disengage from notch 44, to permit the full extension of lock bolt 22, by rotating the lock rapidly back and forth one or possibly two times whereby, latch 84 of member 76 can be made to assume position 90 as depicted in FIG. 8.

Once the lock has been locked with bolt 22 being fully extended as depicted in FIG. 8, it is then impossible to open the lock or withdraw lock bolt 22 by manipulat ing the lock by any means other than a properly cut, smooth fitting key. If the would-be picker attempts to open the lock by retracting bolt 22 by any means other than a properly cut, smooth fitting key, lock bolt 22 will move downward slightly from its position as depicted in FIG. 8, such that latch 84 is permitted to enter notch 44 as depicted in FIG. 9, before all the tumblers of the lock are free, after which any attempt to further withdraw lock bolt 22 is prevented. During any attempt to further withdraw lock bolt 22, the top of notch 44 makes contact with the top of latch 84 and clamps latch 84 against the top surface of the body of lock 12 as depicted in FIG. 10, thereby preventing any further withdrawal of the lock bolt. Although movable member 76 and its latch arm portion 84 can be constructed of thin plastic or any other flexible material, the sheer strength of latch 84 is such that it is not damaged by the maximum pressure which can be exerted through rotation of the lock barrel by a key, picking tools, or other like means.

If a properly cut, smooth fitting key is used to open the lock and retract lock bolt 22, the lock barrel can be rotated rapidly enough so that latch 84 does not have time enough to engage within notch 44 in the side of bolt 22 whereby the lock may be opened in a normal fashion. The inertia of movable member 76 results in a small time delay between the point when latch 84 is released from its withheld position as depicted in FIG. 8 and the point where it has swung into engagement within notch 44 as depicted in FIG. 9, such that the lock may be opened when a properly cut, smooth fitting key is used to rotate the lock in a rapid manner.

The arrangement of device 70 in FIGS. 6 through 13 has been shown in connection with a lock the bolt of which moves in a generally vertical or upright manner, however device 70 when properly modified can be used in a lock arrangement wherein the lock bolt moves in a generally horizontal manner, as depicted in FIG. 14, or in a manner other than vertical or generally upright. In the arrangement depicted in FIG. 14 the body of lock 12 has been rotated degrees in the clockwise direction such that lock bolt 22 now moves in a generally horizontal direction instead of the vertical direction as depicted in FIGS. 6 through 13. Device 70 is arranged on the body of lock 12 and in relation to lock bolt 22 in a manner identical to that as depicted in FIGS. 6 through 11. Since the force of gravity would not tend to pivot member 76 in a direction such that latch 84 thereof is urged into engagement with notch 44, a small weak spring is provided to constantly urge latch 84 into engagement within notch 44 of bolt 22. One end 102 of spring 100 is attached to housing 74 and the opposite end 104 is positioned along the side of portion 78 of pivotal member 76 to urge member 76 to pivot in a counterclockwise direction about fulcrum or pivot point 88. Spring 100 additionally includes a flexible portion 106 which is continually in contact With the right edge of portion 80 of pivotal member 76 to constantly urge portion 80 and entire member 76 to the left to maintain contact with fulcrum or pivot point 88. Loop portion 106 of spring 100 further acts to return pivotal member 76 to fulcrum 88 after the same has been moved to the right to pivot about the fulcrum or pivot point 94 during the extension of bolt 22.

The arrangement depicted in FIG. 14 functions or operates on the same principle as that depicted in FIGS. 6 through 13. That is to say, latch 84 enters notch 44 during attempted picking of the lock, pivoting into engagement during the first small increment of withdrawl of lock bolt 22 before all the tumblers of the lock are freed by the would-be-picker using picking tools. The lock may be operated and opened by a properly cut, smooth fitting key if the key and the lock barrel are rotated in a rapid manner, which is faster than the time required for latch 84 to swing from its withheld position depicted in FIG. 14 into its engaged position within notch 44 after release by the side of lock bolt 22, this time delay resulting from the inertia of pivotal member 76.

While only certain preferred embodiments of this in vention have been shown and described by way of illustration, many modifications will occur to those skilled in the art and it is intended that all such modifications be covered within the true spirit and scope of this invention.

What is claimed as new and what it is desired to secure by Letters Patent of the United States is:

1. In a key operated lock including a locking bolt movable along a path between an extended locked position and a retracted open position, said locking bolt including shoulder means facing in the direction in which said locking bolt is retractable, a dogging means movable into and out of the path of said shoulder means, means for continually urging said dogging means toward the path of said shoulder means, said locking bolt including means for maintaining said dogging means in its inoperative position with respect to said shoulder means, said dogging means being responsive to release of said maintaining means for movement into the path of said shoulder means to prevent retraction of said locking bolt from its substantially extended locked position, said locking bolt being freely retractable when said dogging means is maintained out of the path of said shoulder means.

2. In the key operated lock as defined in claim 1 wherein said means for continually urging said dogging means toward the path of said shoulder means is a spring.

3. In the key operated lock as defined in claim 1 wherein said locking bolt is movable along a generally vertical path and wherein said dogging means are by the weight thereof continually urged toward the path of said shoulder means.

4. In the key operated lock as defined in claim 1 wherein said lock includes a housing, a pivotal member mounted adjacent to said housing and having portions closely adjacent said locking bolt and shoulder means, said dogging means being connected to and forming a portion of said pivotal member, said dogging means being movable into and out of the path of said shoulder means upon pivotal movement of said pivotal member.

5. In the key operated lock as defined in claim 1 wherein said locking bolt has an outwardly opening notch positioned within the side thereof facing said dogging means, said shoulder means constituting a part of said notch, said dogging means being movable into and out of engagement within said notch when said notch and dogging means are in alignment.

6. In a key operated lock including a locking means movable along a path between an extended locked position and a retracted open position, said locking means including shoulder means facing in the direction in which said locking means is retractable, a dogging means movable into and out of the path of said shoulder means, said dogging means being urged toward the path of said shoulder means, said lock including means for maintaining said dogging means in its inoperative position with respect to said shoulder means when said locking means is fully extended, said dogging means including means moving it into operative position in the path of said shoulder means upon a predetermined retracting movement of said locking means from its fully extended position after a predetermined delay from the initial movement of said locking means from its fully extended position toward its retnacted position, said locking means being freely retractable without said dogging means moving into said operative position with respect to said shoulder means upon movement of said locking means beyond said predetermined retracting movement in less time than said predetermined delay of said dogging means.

7. In the key operated lock as defined in claim 6 further including spring means to urge said dogging means toward the path of said shoulder means.

8. In the key operated lock as defined in claim 6 Wherein said locking means is movable along a generally vertical path and wherein said dogging means are by the weight thereof urged toward the path of said shoulder means.

9. In the key operated lock as defined in claim 6 wherein said lock includes a housing, a pivotal member mounted adjacent to said housing and having portions closely adjacent said locking means and shoulder means, said dogging means being connected to and forming a portion of said pivotal member, said dogging means being movable into and out of the path of said shoulder means upon pivotal movement of said pivotal member.

10. In the key operated lock as defined in claim 6 wherein said locking means includes a lock bolt movable along a path between an extended locked position and a retracted open position, said bolt having an outwardly opening notch positioned within the side thereof facing said dogging means, said shoulder means constituting a part of said notch, said dogging means being movable into and out of engagement with said notch when said notch and dogging means are in alignment.

11. In the key operated lock as defined in claim 10 further including spring means to urge said dogging means into engagement within said notch position within the side of said lock bolt.

12. In the key operated lock as defined in claim 10 wherein said lock includes a housing, a pivotal member mounted adjacent to said housing and having portions closely adjacent said lock bolt and notch within the side of said lock bolt, said dogging means being connected to and forming a portion of said pivotal member said dogging means being movable into and out of engagement within said notch when said notch and dogging means are in alignment and upon pivotal movement of said pivotal member.

13. In the key operated lock as defined in claim 12 wherein said lock bolt is movable along a generally vertical path and wherein said dogging means portion of said pivotal member is by the weight thereof urged into engagement within said notch.

14. In the key operated lock as defined in claim 12 wherein said means for maintaining said dogging means portion of said pivotal member in its inoperative disengaged position with respect to said notch when said lock bolt is fully extended is the side of said lock bolt adjacent to said notch.

15. In the key operated lock as defined in claim 12 wherein said pivotal member further includes an outwardly extending tab, said tab being adapted and arranged to be engaged by said lock bolt upon full extension thereof to pivot said pivotal member and move said dogging means portion of said pivotal member out of engagement with said notch, said lock bolt and tab maintaining said dogging means in its inoperative disengaged position with respect to said notch when said lock bit is fully extended.

16. In the key operated lock as defined in claim 12 wherein said lock bolt is movable along a generally vertical path, said pivotal member being mounted adjacently above said housing of said lock and including portions extending closely adjacent the notched side of said lock bolt, said pivotal member and lock bolt lying in the same general vertical plane, said pivotal member including a downwardly extending ta-b portion, said tab portion being adapted and arranged to be engaged by the top of said lock bolt upon full extension thereof to pivot said pivotal member and move said dogging means portion of said pivotal member out of engagement with said notch, said tab and top of said lock bolt maintaining said dogging means in its inoperative disengaged position with respect to said notch when said lock bolt is fully extended.

17. In the key operated lock as defined in claim 12 wherein said pivotal member further includes a pivot arm portion spaced from said dogging means, and a first pivot means engaging a part of said pivot arm portion for pivoting said pivotal member and dogging means thereabout.

18. In the key operated lock as defined in claim 17 wherein said pivotal member is elongated and wherein said dogging means is adjacent one end portion thereof, said pivot arm portion being located adjacent the other end portion of said pivotal member and said pivot arm portion extending in a direction laterally opposite to said dogging means.

19. In the key operated look as defined in claim 17 wherein said pivot arm portion includes another part spaced outwardly of said part, a second pivot means positioned laterally outward of said first pivot means and facing in a direction generally opposite thereto, said second pivot means being adapted and arranged to selectively engage said other part of said pivot arm portion when said pivot arm portion is moved from its contact with said first pivot means whereby said pivotal member and dogging means portion thereof is pivotal about said second pivot means.

References Cited UNITED STATES PATENTS 591,200 10/1897 Stevenson 70-1.5 1,398,642 11/1921 Lewis 70-1.5 1,620,775 3/1927 Meilink 701.5 2,228,971 1/1941 Pankrotz 70--1.5

MARVIN A. CHAMPION, Primary Examiner B. I. MCCARTHY, Assistant Examiner UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 5 1 069 Dated May 12, 1970 Inventor(s) Ewing awrence, Jr,

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 9, after "attempted" omit the words to operated Column 8, line 20, the word "with" should read within Column 8, line 55, "bit" should read bolt SIGNED AND EALED swam wnmm x. samnnm, .m. Attesting Officer Gomissium of Patent:

FORM PO-IOSO (10-69l uscoMM-Dc 603764 69 9 U 5. GOVERNMENT PRINTING OFVICE I969 O-J66 33 

